Treating hydrocarbon oils



D. T. DAY. TREATING HYDROCARBON OILS.

APPLICATION FILED APR. 30, 191s.

Patented Mar. 29, 1921.

narran stares rarest carica TRATING- HYDROCRBON OILS.

Specication of Letters Patent.

Patented Mar. 29, 1921.

application med Anvil so, 191s. serial No. 231,6s.

Toy all whom t may concern Be it known that I, DAVID T. DAY, a citizen of the United States, residing at Washington, in the District of, Columbia, have invented new and useful Improvements in Treating Hydrocarbon Oils, of which the following is a specification.

This invention relates to a process of converting into gasolene such hydrocarbon residues as acid tar, sludge acid, or acid sludge, and material such as may be formed incident to the treatment ofi hydrocarbon oils with sulfuric acid. rlhe invention also includes the treatment of pitches, tar, or asphaltic oils such as occur inmature.

It has long been recognized that the cracking of the above mentioned materials into gasolene is impractical in the forms of appa- .ratus usually employed for cracking, on account of the large amount of carbon formed during the thermal decomposition of such oil residues.

This invention now discloses the fact that when such residues are dissolved in any appreciable percentage in other oils more fluid in their character, and preferably in oils which do not crack as easily as these tar oils, it is practical to pass the solution of these oil residues in such oils through a cracking apparatus at a lower temperature than that required for the cracking of a solvent oil. Also that these residues, when so cracked yield gasolene of good quality, and frequentlyT the much more valuable aromatic hydrocarbons such as benzol and toluol in admixture with other cracked products. The presence of sulfuric acid residues in these oils in no way interferes with the cracking process, but as already demonstrated by me, Patent No. 1,221,698,the presence of the sulfur is favorable to the cracking of these oils, the action possibly being catalytic in its character.

In carrying out this process, the hot heavy residual oil remaining after any cracking process, and from which the light gasolene has been extracted by distillation or fractional condensation, is run through a pipe, which carries the oil to tanks containing the acid sludge. Such residual oil is described rin the claims as petroleum residues. rIhe oil then dissolves the acid sludge in such proportion as may prove most advantageous, usually lfrom 10 to 50 per cent. The hot oil now carrying the acid sludge 1n solution or suspension, is returned to the feed tank of the cracking apparatus and then passed through a. cracking chamber, preferably at a temperature where cracking will be chiefly accomplished in the acid sludge dissolved in the suitable menstrum. It is found that the acid tar or sludge is largely-eventually completely-cracked into lighter products, and the dissolving oil can be then pumped back to take upy another supply of acid tar, again serving as a. solvent in which the acid tar is returned to the cracking apparatus, the former result being repeated. The temperatures found most advantageous for cracking such acid tar vary according toconditions of pressure and quality of the tar. possibly from 600O F. to 1000o F., a temperature of 600'O F. to 7000 F. being preferred. y

The process may be conducted in any suitable form of apparatus. One form of apparatus is vshown diagrammatically in the drawing forming ai part of this application. 1n the drawing, 1 is a. tank containing oil in which an amount of acid tar or similar material has been dissolved. 2 is a pump adapted to force the material froml the tank 1 through the pipe 3 to a cracking furnace 4; which may be of the usual vapor tube type. Material from the cracking furnace 4 is led through a pipe 5 to a fractional condensation chamber 6, from the bottom of which the hot oil which has not been cracked escapes into a pipe 7, which carries this hot oii to a tank 8, containing the acid tar to be dissolved. 9 is a pipe extending from this tank of acid ar and adapted to carry the solvent oil, now charged with the heavy tar 10 is the exit pipe residue, to the tank 1. extending from the top of the fractional condensation tower from which latter the gasolene formed, and the permanent gases formed, are conducted through a suitable condensing coil 11 and into a tank 12 for holding the condensed gasolene. Untreated acid tar or sludge may be introduced into the tank 8 through an inlet pipe 8a. Fresh relatively iuid oil such as crude oil, to be used as the solvent oil may be introduced into the tank 1 through an inlet pipe la. The final gasolene product may be drawn from the tank 12 through a pipe 12a. Valves may be provided in the pipes 3, 5, 7, 8a, 12a and 13. as well as in other parts of the apparatus to provide for regulation of temperatures `and pressures as desired and to render convenient the operation of the ap aratus to perform the process described an claimed. Permanent gases are led from the tank l2 by means of a pipe 13 to any type of gas reservoir, not shown.

From the foregoing it will beV `clear that the present invention has provided a process for,` utilizing materials Which heretofore could not be used. By the use of the present invention it will now be possible to obtain valuable products from asphaltc oils, acid tars and sludges which have been formed in the treatment of oils with acids.

I claim:

l. The process of obtaining hydrocarbon oils having low boiling points from hydrocaibon oils having high boiling points which comprises makin a solution of a mixture of the original high boiling material to be treated With petroleum residues having higher cracking points, subjecting the mixtuie to a heat treatment of at least 6000 F. to bring about the desired cracking of the original material but at a temperature lower than required to crack substantial amounts of the solvent material, subjecting the material so treated to a separating treatment to remove the low boiling point material produced from the original material, and returning the residues for mixing With additional high boiling materials.

2. The process of obtaining hydrocarbon oils having low boiling points from petroleum residues containing acid tar which comprises making a solution of the original residues containing acid tar with petroleum residues having higher cracking points, subjecting the mixture to a heat suiiicient to bring about cracking of at least a portion of the loriginal material but below the cracking point of the higher cracking point material, subjecting the material so treated to a separating treatment to remove the low boiling material produced from the original material, and returning the residues for mixing with original petroleum residues containing acid tar.

3. The process of obtaining hydrocarbon oils having low boiling points from petroleum residues containing acid tar which comprises making a solution of a mixture of the original residues containing acidy tar with petroleum residues having higher cracking points, subjecting the mixture to a heat treatment of at least 600O F. to bring about the desired cracking of the original material, and subjecting the material so treated to a separating treatment to remove the low boiling material produced from the original material.

4. The process of obtaining hydrocarbon oils having low boiling points from petroleum residues containing acid tar which comprises dissolving such petroleum residues in a solvent, treating a solution of such material with a temperature of at least 600 F. but below the cracking point of the solvent to bring about the desiredcracking of at least a portion of the residues containing acid tar, and separating the materials so treated.

5. The process of obtaining hydrocarbon oils having low boiling points from petroleum residues containing acid tar which comprises dissolving such petroleum residues in a solvent having a higher cracking point than that of the acid tar, heat treating a solution of such materials to a temperature below the cracking point of the solvent hydrocarbon to bring about the desired cracking of the original residue containing the acid tar7 and separating the materials so treated.

6. The process of obtaining hydrocarbon oils having lovv boiling points from petroleum residues containing acid tar which comprises dissolving such petroleum residues in a solvent having a higher cracking point than that of the acid tar, heat treating a solution of such materials to a temperature of at least 600O F. below the cracking point of the solvent hydrocarbon to bring about the desired cracking of the original residue containing the acid tar, separating the materials so treated to remove the 10W boilinfr point hydrocarbon so produced, and using the residues as solvents for the additional fresh petroleum acid tar containing material.

In testimony whereof l have hereunto set m hand.

y DAVID T. DAY. 

